Casein glue



Patented Apr. 28, 1925.

HENRY L. PRESTHOLDT, F MINNEAPOLIS, MINNESOTA.

CASEIN GLUE.

No Drawing.

To all whom it may concern:

Be it known that I. HENRY L. Puns'r- IIOLDT,\ a citizen of the United States, residing at Minneapolis,in the county of Hen- I nepin and State of Minnesota, have invented certain new and useful Improvements in Casein Glue; and I do hereby declare the following to be a full, clear, and exact description of the invention such as will enable,

others skilled in the art to which it appertains to make and use the same.

My invention provides a new composition of matter, herein designated as casein glue, but which, from its broader aspect, is

an. adhesive composition adapted to be used, by itself or commingled with other substances, as an adhesive coating. p

i In this improved composition, casein is used as the adhesive base and is commingled with sodium formate, calcium hydroxide,

sodium'sulphite and alum.

I have obtained a highly efficient glue or adhesive by the use of the above noted substances in accordance with the following formula: P

,Casein 50 to 75 parts. Sodium formate 1 to 6 parts. Calciumhydroxide- 10 to parts. Sodium sulphite 3 to 10 parts.

30 Alum 2 to 6 parts.

The above noted substances are commingled in dry powdered form and are sold in that condition. 'When the adhesive composition is to be used, it will be introduced into water to form emulsion, and it is then, of

course, that the chemical reactions that develop the adhesive qualities of the composition, will take place. After these reactions have taken place, the emulsion is adapted to 40 be used as a glue or as a coating or to be commingled with other substances, such as paint or calclmlne, which contain color pigm'ents.

5 and when casein is precipitated with a forl/Vhen desired, however, the color producing pigments may be commingled with thcdry compositlon. When the com- Application filed April 17, 1922. Serial No. 554,198.

mic acid or a formate, it will remain in for casein. In an aqueous solution, colloids are formed, which, together with a calcium caseinate, produces a highly water-resistant adhesive. Sodium sulphite imparts a great penetrating value to the adheslve and, in a small way, loosens the grain of the wood, forming sulphite of cellulose, making a perfect joint. Alum prevents the glue mixture from becoming too viscous and prolongs its liquid life. Sodium formate, due to its antiseptic properties, retards the formation of nitrogen.

Sodium sulphite 'is essential to the production of glue having the important properties herein specified, but the alum, while important, is not essential and may be omitted, especially in glues that are not necessarily'kept long in liquid form.

What I claim is v l 1. An adhesive composition? comprising the following ingredients in substant ally the following proportions:

Casein '50 to 75 parts. A salt of formic I acid 1 to 6'parts.

Calciumhydroxide 10 to 30 parts. Sodium sulphite 3 to-10 parts. 2. An adhesive composition made inaccordance with the following formula Casein i- 50 to 75 parts. Sodium formate 1 to 6 parts. Calciumhydroxidm 10 to 30 parts. Sodium sulphite 3 to 10 parts. Alum; 2 to 6 parts, In testimony whereofI affix my signature.

l HENRY L. PRESTHOLDT. 

